Primer mide koryokarsinomu son derece nadir ve yüksek derecede malign bir tümördür. 60 yaşında bir erkek, mide ağrısı ve siyah dışkılama şikayetleri ile başka bir hastaneye başvurmuştu. Üst gastrointestinal endoskopide mide korpusu ve antrumu dolduran ülserovejetan büyük bir tümör görülmüştü. Endoskopik biyopsi ile mide adenokarsinomu tanısı konulmuştu. Hasta tedavi için hastanemize kabul edildi. Kanama ile komplike olmuş mide adenokarsinomu olarak değerlendirildi. Cerrahi gözlemde mide korpusundan kaynaklanan kitlenin transvers kolon ve pankreasa invaze olduğu görüldü. Çölyak aksta konglomere lenfadenopatiler vardı ve çölyak damarları invaze etmiş idi. Palyasyon için subtotal gastrektomi ve genişletilmiş sağ hemikolektomi yapıldı. Patolojik incelemede sitotrofoblastlar ve sinsityotrofoblastlardan oluşan iki hücre paterninin tipik özellikleri görüldü. Tümör sadece koryokarsinomdan ibaretti. Koryokarsinom kesin tanısı için immünohistokimyasal testler yapıldı. Beta-HCG ve EMA boyama pozitifti. Hasta ameliyattan 3 hafta sonra mide koryokarsinomu tanısı nedeniyle kontrole çağrıldı. Serum beta-HCG düzeyi458 mIU/mL idi (normal aralık,

Primary choriocarcinoma of the stomach is an extremely rare and highly malignant tumor. A 60 years old man visited another hospital for the chief complaint of the stomachache and black stools. A large ulcero-vegetative tumor occupying the gastric body and antrum was seen in the upper gastrointestinal endoscopy. It was diagnosed as gastric adenocarcinoma by endoscopic biopsy. The patient admitted to our hospital for treatment. The patient was assessed as a gastric adenocarcinoma complicated with hemorrhage. In the exploration, it was observed that the mass arising from gastric body was invaded the transverse colon and pancreas. The lymphadenopaties in the celiac axis were conglomerated and had invaded the celiac vessels. A subtotal gastrectomy and an extended right hemicolectomy were performed for palliation. In pathological findings, typical characteristics of two cell pattern consisting of syncytiotrophoblasts and cytotrophoblasts were observed. The tumor consisted of only choriocarcinoma. For the definite diagnosis of choriocarcinoma, immunohistochemi- cal tests were performed. Beta-HCG and EMA staining were positive. The patient was invited for control because of gastric choriocarcinoma three weeks later surgery. His serum beta-HCG level was 458 mIU/mL (normal range, <0.5 mIU/mL). For the differantiation from the primary choriocarcinoma in the testis or mediastinum, testicular ultrasonography and chest CT were performed. Abnormal findings were not detected in the tests, so it was diagnosed as primary gastric choriocarcinoma. The patient refused chemotherapy. Three months later, he had inguinal lymphadenopaties and multiple metastases in lung. He died 5 months after surgery because of respiratory failure.